TWI488100B - Capacitive touch screen - Google Patents

Capacitive touch screen Download PDF

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Publication number
TWI488100B
TWI488100B TW102122004A TW102122004A TWI488100B TW I488100 B TWI488100 B TW I488100B TW 102122004 A TW102122004 A TW 102122004A TW 102122004 A TW102122004 A TW 102122004A TW I488100 B TWI488100 B TW I488100B
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TW
Taiwan
Prior art keywords
sensing electrodes
substrate
touch
touch screen
touch control
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Application number
TW102122004A
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Chinese (zh)
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TW201501004A (en
Inventor
liang-hua Mo
Chen Li
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Focaltech Systems Ltd
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Priority to TW102122004A priority Critical patent/TWI488100B/en
Publication of TW201501004A publication Critical patent/TW201501004A/en
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Publication of TWI488100B publication Critical patent/TWI488100B/en

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Description

Capacitive touch screen

The invention relates to a touch display device, in particular to a capacitive touch screen.

At present, capacitive touch screens are widely used in various electronic products, and have gradually penetrated into various fields of people's work and life. More and more capacitive touch screens support the touch operation of passive pens and hands, but the amount of mutual capacitance change caused by the touch of the hand and the passive pen is different, and the mutual capacitance caused by the touch of the hand The amount of change is large. The detection of the touch position of the general hand is realized by the principle of mutual capacitance. Because the touch pen has a small area of contact, it is often insufficient to cause sufficient mutual capacitance change. Therefore, passive The touch detection of the pen is generally realized by the self-capacitance principle. However, when a plurality of passive pens are used for the touch operation at the same time, the Ghost point problem often occurs when the screen is detected by the self-capacitance principle, and therefore, the self-capacity is caused. Touch screens are not able to achieve true multi-touch.

Therefore, how to accurately detect the touch position of the hand and the passive pen, and realize the multi-touch is an object that the inventor of the present invention and those skilled in the related art are eager to improve.

In view of this, the embodiment of the invention provides a capacitive touch The screen comprises: a substrate, a plurality of sensing electrodes and a touch control chip. A plurality of sensing electrodes are disposed on the substrate, and the sensing electrodes are arranged in a two-dimensional array. The touch control chip is placed on the substrate, and the touch control chip and each of the sensing electrodes are respectively connected by wires, and the touch control chip is configured to detect each sensor by using a detection circuit with adjustable test precision. The touch signal is determined by the amount of self-capacitance change of the electrode.

In the capacitive touch screen disclosed in the embodiment of the present invention, the touch control wafer and each of the sensing electrodes are respectively connected by wires and disposed on the substrate, and the plurality of sensing electrodes are arranged in a two-dimensional array, and the sensing electrodes are There is no physical connection, so that real multi-touch can be realized, and the detection circuit with adjustable touch precision can be used to detect the self-capacitance change of each sensing electrode, so that the capacitive touch screen can be based on Different test precisions are set for different touch objects, thereby achieving accurate detection of the touch position.

The detailed features and advantages of the present invention are set forth in the Detailed Description of the Detailed Description of the <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> <RTIgt; The objects and advantages associated with the present invention can be readily understood by those skilled in the art.

2a-2d‧‧‧Induction electrodes

10‧‧‧Touch Control Wafer

11‧‧‧Capacitive touch screen

15‧‧‧Optical adhesive

16‧‧‧Substrate

17‧‧‧heteroconductive film

18‧‧‧ Coverage

19‧‧‧Induction electrodes

21‧‧‧ Touch

22‧‧‧Bus

23‧‧‧clock control circuit

24‧‧‧ drive source

25‧‧‧Detection circuit

41‧‧‧ drive source

42-43‧‧‧ Capacitance

45‧‧‧Measurement unit

V1-V3‧‧‧ voltage

S1/S2‧‧‧ controlled switch

V3_s‧‧‧ high potential

V3_t‧‧‧ low potential

Cx‧‧‧ground capacitance

Cb‧‧‧Adjust capacitor

Phase1-phase3‧‧‧ phase

S701‧‧‧ drive sensing electrode

S702‧‧‧Adjust test accuracy

S703‧‧‧Detection sensing data

S704‧‧‧Determining the touch position

FIG. 1 is a schematic diagram of a capacitive touch screen according to an embodiment of the present invention.

2 is a top plan view of an array of sensing electrodes according to an embodiment of the present invention.

FIG. 3 is a working circuit of a sensing electrode according to an embodiment of the present invention.

4A-4C are schematic diagrams showing scanning timings of sensing electrodes according to an embodiment of the present invention.

FIG. 5 is a circuit diagram of a touch detection circuit according to an embodiment of the present invention.

FIG. 6 is a timing diagram of a touch detection circuit according to an embodiment of the present invention.

FIG. 7 is a flowchart of a touch detection method according to an embodiment of the present invention.

In the following, the technical solutions of the embodiments of the present disclosure will be described in conjunction with the accompanying drawings in the embodiments of the present disclosure. It is to be understood that the described embodiments are only a part of the embodiments of the invention. Any other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without any creative work should fall within the protection scope of the present invention. For ease of explanation, the cross-sectional view showing the structure is not partially enlarged in accordance with the general scale. Moreover, the drawings are merely exemplary and should not be construed as limiting the scope of the invention. In addition, the actual production should include three-dimensional dimensions of length, width and depth.

FIG. 1 is a schematic diagram of a capacitive touch screen according to an embodiment of the present invention. As shown in FIG. 1 , the capacitive touch screen 11 includes: a substrate 16; a plurality of sensing electrodes 19 disposed on the substrate 16 , the plurality of sensing electrodes 19 are arranged in a two-dimensional array; and disposed on the substrate 16 Touch control wafer 10. The touch control chip 10 and each of the sensing electrodes 19 are respectively connected by wires. The touch control chip 10 is configured to detect the self-capacitance change of each sensing electrode by using a detection circuit with adjustable test precision, thereby determining the touch signal and detecting The circuit will be described in detail later.

Substrate 16 may be transparent, such as a glass substrate or a flexible substrate; substrate 16 may also be opaque, such as a printed circuit board. A plurality of sensing electrodes 19 are disposed on the substrate 16, and the plurality of sensing electrodes 19 are arranged in a two-dimensional array, which may be a rectangular array or a two-dimensional array of any other shape. For the capacitive touch screen 11, each of the sensing electrodes 19 is a capacitive sensor, and the capacitance of the capacitive sensor changes when the corresponding position on the touch screen is touched.

In some implementations, a cover layer 18 (Cover Lens) is disposed over the sensing electrode 19 to protect the sensing electrode 19.

In some implementations, an optical paste 15 (Optical Clear Adhesive; OCA) is disposed over the sensing electrode 19. Furthermore, the optical glue 15 is disposed between the cover layer 18 and the sensing electrode 19.

Each of the sensing electrodes 19 is connected to the touch control wafer 10 by wires, and the touch control wafer 10 is disposed on the substrate 16. Since each of the sensing electrodes 19 is connected by wires, the touch control wafer 10 has a large number of pins. Therefore, placing the touch control wafer 10 on the substrate 16 can avoid the difficulty of conventional packaging.

In some implementations, the touch control wafer 10 can be chip-on-glass (COG) or chip-on-film (COF) or chip-on-chip (Chip-). The on-Board (COB) mode is disposed on the substrate 16. As shown in FIG. 1, an anisotropic conductive film (ACF) 17 may be present between the touch control wafer 10 and the substrate 16.

In addition, conventional flexible circuit board (FPC) connections are required The hardware reserves space for the touch control chip 10 and the flexible circuit board, which is not conducive to system simplification. The touch control wafer 10 and the touch screen are integrated by the glass flip chip or the flexible flip chip, which significantly reduces the distance between the two, thereby reducing the overall volume. In addition, since the sensing electrode 19 is generally formed by etching indium tin oxide (ITO) on the substrate 16, and the touch control wafer 10 is also located on the substrate 16, the connection between the two can be passed once. The indium tin oxide etch is completed, which significantly simplifies the manufacturing process.

Fig. 2 is a plan view of a sensing electrode array according to an embodiment of the present invention. It should be understood by those skilled in the art that FIG. 2 shows only one arrangement of the sensing electrodes 19. In a specific implementation, the sensing electrodes 19 can be arranged in any two-dimensional array. In addition, the spacing of the sensing electrodes 19 in either direction may be equal or unequal. It will also be understood by those skilled in the art that the number of sensing electrodes 19 can be more than the number shown in FIG.

It will be understood by those skilled in the art that as shown in Fig. 2, only one shape of the sensing electrode 19 is shown. According to other embodiments, the shape of the sensing electrode 19 may be rectangular, rhombic, circular or elliptical, or may be irregular. The patterns of the sensing electrodes 19 may be uniform or inconsistent. For example, the sensing electrode 19 in the middle has a rhombic structure and the edges have a triangular structure. In addition, the size of each of the sensing electrodes 19 may be uniform or inconsistent. For example, the inner sensing electrode 19 has a large size and a small size on the edge, which is advantageous for the touch precision of the trace and the edge.

Referring to FIG. 2, each of the sensing electrodes 19 has a lead wire which is disposed in a gap between the sensing electrodes 19. In general, wires Try to be as uniform as possible and keep the traces as short as possible. In addition, the wire routing range is as narrow as possible under the premise of ensuring a safe distance, thereby leaving more area of the sensing electrode 19, so that the sensing is more accurate.

Each of the sensing electrodes 19 can be connected to the bus 22 by wires. The bus 22 connects the wires directly or after a certain order to the pins of the touch control wafer 10. For large screen touch screens, the number of sensing electrodes 19 can be very large. In this case, all the sensing electrodes 19 can be controlled by a single touch control chip 10; or, by dividing the screen, the sensing electrodes 19 of different regions can be separately controlled by the plurality of touch control wafers 10, and multiple touch controls are performed. Clock synchronization is possible between the wafers 10. At this time, the bus 22 can be divided into a plurality of bus sets for connection with different touch control wafers 10. Each touch control wafer 10 controls the same number of sensing electrodes 19 or controls a different number of sensing electrodes 19.

For the sensing electrode array shown in Fig. 2, the wiring can be implemented on the same layer of the sensing electrode array. For other types of sensing electrode arrays, if the same layer routing is difficult to implement, the wires may be disposed in another layer different from the layer in which the sensing electrode array is located, and the sensing electrodes are connected through the via holes.

The sensing electrode array shown in FIG. 2 is based on the self-capacitance touch detection principle. Each of the sensing electrodes 19 corresponds to a specific position on the screen. In FIG. 2, the sensing electrodes 2a/2b/2c/2d represent different sensing electrodes. When the touch 21 occurs at a position corresponding to a certain sensing electrode, the electric charge on the sensing electrode changes, and therefore, the electric charge (current/voltage) on the sensing electrode is detected, and it is possible to know whether or not the sensing electrode has a touch event. In general, this can be quantified as a number by analog analog converter (ADC) conversion analogy. achieve. The amount of charge change of the sensing electrode is related to the area covered by the sensing electrode. For example, the amount of charge change of the sensing electrode 2b and the sensing electrode 2d in FIG. 2 is larger than the amount of charge change of the sensing electrode 2a and the sensing electrode 2c.

Each of the positions on the screen has corresponding sensing electrodes, and there is no physical connection between the sensing electrodes. Therefore, the capacitive touch screen provided by the embodiments of the present disclosure can realize true multi-touch, avoiding the prior art. The ghost point problem of capacitive touch detection.

The sensing electrode layer can be combined with the display screen by surface bonding, or the sensing electrode layer can be displayed inside the screen, such as an in-cell touch screen, and the sensing electrode layer can be displayed on the screen. Surfaces, such as on-Cell touch screens.

FIG. 3 is a working circuit of the sensing electrode according to the embodiment of the present invention. The sensing electrode 19 is simultaneously connected to the driving source 24 and the detecting circuit 25. When the self-capacitance of the sensing electrode 19 changes, the amount of change can be detected by the detecting circuit 25. The sensing electrode 19 is driven by a drive source 24. Here, the driving source 24 is a power source, that is, the driving source 24 may be a voltage source or a current source. For different sensing electrodes 19, the driving source 24 does not necessarily have to have the same structure. For example, a voltage source may be partially used, and a current source may be partially used. Further, for different sensing electrodes 19, the frequency of the driving source 24 may be the same or different. The clock control circuit 23 controls the clock of the operation of each of the drive sources 24.

The driving clock of each of the sensing electrodes 19 has various options. As shown in Figure 4A, all of the sensing electrodes are driven simultaneously and simultaneously detected. In this way, the time required to complete a scan is the shortest, and the number of driving sources is the largest (consistent with the number of sensing electrodes).

As shown in Fig. 4B, the driving sources of the sensing electrodes 19 are divided into groups, each of which sequentially drives the electrodes in a specific region. This method can realize different time sharing of different electrodes by the same driving source, thereby saving the number of driving sources, but increasing the scanning time. However, by selecting the appropriate number of groups, the driving source multiplexing and scanning time can be compromised. For example, if the scan time of each electrode is equal to Ts and the total scan time of one frame is T, then K=T/Ts is defined, and the larger the K value, the less time the drive source can be used. Complete a full screen scan. For example, K=2 means that scanning can be done with only 1/2 of the drive source, K=3, representing only 1/3 of the number of drive sources.

Figure 4C shows the scanning mode of the conventional mutual capacitance touch detection. Assuming that there are N drive channels (TX), the scan time of each TX is Ts, and the time of scanning one frame is N*Ts. With the sensing electrode driving method of the embodiment, all the sensing electrodes can be detected together, and the time for scanning one frame is only Ts. That is to say, the scheme of the embodiment can increase the scanning frequency by N times compared with the conventional mutual capacitance touch detection.

For a mutual capacitive touch screen with 40 drive channels, if the scan time of each drive channel is 500 microseconds (μs), the scan time of the entire touch screen (one frame) is 20 milliseconds (ms), ie The frame rate is 50 Hz. 50Hz often does not meet the requirements of a good experience. The solution of the embodiments of the present disclosure can solve this problem. By using the sensing electrodes arranged in a two-dimensional array, all the electrodes can be simultaneously detected, and the frame rate reaches 2000 Hz with the detection time of each electrode being maintained for 500 microseconds (μs). This greatly exceeds the application requirements of most touch screens. The extra scan data can be used by the digital signal processing terminal for, for example, anti-jamming Or optimize the touch track for better results.

The In-Cell touch screen uses the vertical blanking interval (VBlank, also known as field reversal) of each frame to scan, but the field blanking time per frame is only 2 to 4 milliseconds ( Ms), the conventional scanning time based on mutual capacitance is often 5ms or more. In order to achieve the use of the embedded screen, the scanning time of the mutual capacitance touch detection is usually reduced, specifically, the scanning time of each channel is reduced. This method reduces the signal-to-noise ratio of the embedded screen (Signal-to-noise ratio). SNR or S/N) affects the touch experience. The solution of the embodiments of the present disclosure can solve this problem. For example, there are ten drive channels and a conventional mutual capacitance touch detection embedded time screen with a scan time of 4ms, and the scan time per channel is only 400μs. By employing the scheme of the embodiment of the present disclosure, all electrodes are simultaneously driven and detected, and all the electrodes are scanned for only 400 μs. If you press the embedded screen above and the scan time is 4ms, there is still a lot of time left. The saved time can be used for other detections such as multiple repeated detection or variable frequency detection, thereby greatly improving the signal-to-noise ratio and anti-interference ability of the detection signal, so as to obtain a better detection effect.

FIG. 5 is a diagram of a touch detection circuit according to an embodiment of the present invention, and is also a detailed description of the detection circuit 25 in FIG. 3. The detection circuit 25 detects the self capacitance of each of the sensing electrodes. The self-capacitance of the sensing electrode can be its capacitance to ground.

As an example, a charge detection method can be employed. As shown in Fig. 5, the drive source 41 supplies a constant voltage V1. Voltage V1 can be positive, negative or ground. Two controlled switches S1/S2, electric The capacitance 42 represents the capacitance Cx of the sensing electrode to the ground. The value of the capacitance Cx to the ground is fixed when the sensing electrode has no touch. Once there is a touch on the sensing electrode, the value of the capacitance Cx to the ground changes. The measuring unit 45 can clamp the input voltage to the voltage source V2, and convert the electric charge into a voltage by using the capacitor 42 and then send it to an analog digital converter (ADC) for measurement. Actually, it is determined according to the change of the voltage measured by the measuring unit 45. The change of the ground capacitance Cx of the sensing electrode determines whether there is a touch on the sensing electrode and a specific touch position. The capacitor 43 is a regulating capacitor Cb (or a variable capacitor) having a known capacity and an adjustable size. The adjusting capacitor Cb is connected to the voltage V2 at one end and connected to the voltage V3 at the other end, wherein the value of the voltage V3 is variable. The function of the adjustment capacitor Cb is to adjust the test accuracy of the measuring unit 45. As another example, a current source can also be employed, or its self-capacitance can be obtained by sensing the frequency of the electrodes.

FIG. 6 is a timing diagram of the touch detection circuit according to an embodiment of the present invention. The charge measurement process of FIG. 5 can be divided into several stages, and FIG. 6 shows several key stages.

Please refer to Fig. 6. At high potential, the controlled switch S1 and the controlled switch S2 are connected. When the potential is low, the controlled switch S1 and the controlled switch S2 are disconnected. Among them, the voltage V3 will vary between the high potential V3_s and the low potential V3_t. When the measuring unit 45 is at a high potential, the representative circuit is performing sampling quantization, and when the measuring unit 45 is at a low potential, the circuit is in a waiting state. The change in the amount of charge on the sensing electrode from no touch to touch is described in detail below.

When there is no touch on the electrode, in the phase phase1 phase, the controlled switch S1 is closed, the controlled switch S2 is opened, and the voltage source V3 is high. In the potential V3_s state, the upper plate of the ground capacitance Cx is charged to the voltage V1 supplied from the drive source 41. At this time: the charge Qx=Cx*V1 on the ground capacitance Cx; the charge Qb=Cb*(V2-V3_s) on the adjustment capacitor Cb; and the charge Q45=0 on the 45 side.

In the phase phase 2 phase, the controlled switch S1 is turned off, the controlled switch S2 is closed, the voltage V3 is changed from the high potential V3_s to the low potential V3_t state, and the ground capacitance Cx is charged and exchanged with the measuring unit 45 and the adjusting capacitor Cb. : The charge Qx=Cx *V2 on the capacitance Cx to ground; the charge Qb=Cb*(V2-V3_t) on the adjustment capacitor Cb.

Since the charge is conserved during the phase phase1 to the phase phase2, Qx+Qb+Q45 are equal in two stages, and the charge measured by the measuring unit 45 in the phase phase 2 phase can be obtained: Q45=(Cx *V1+Cb *(V2-V3_s))-(Cx *V2+Cb*(V2-V3_t))=Cx*(V1-V2)-Cb(V3_s-V3_t).

That is, there is no voltage measured by the measuring unit 45 when touch: V45=K*Q45=K*(Cx*(V1-V2)-Cb(V3_s-V3_t)) (1).

Where K represents a gain, in the circuit, the charge is generally converted into a voltage by a capacitor, and the gain K is a configurable value.

In the phase phase3 phase, the controlled switch S1 is still open, the controlled switch S2 is closed, the charge transfer between the nodes is balanced, and the measuring unit 45 begins to quantize the charge/voltage values.

It can be seen from equation (1) that when Q45 is quantized and measured After that, only one capacitance of the capacitance value to the ground capacitance Cx is unknown, so the capacitance value of the original capacitance Cx to the ground can be obtained.

In order to ensure the accuracy of the data, the phase phase1 to the phase phase3 process can be repeated, and the capacitance values of the plurality of capacitances C0 to the ground are measured, and then averaged.

When there is touch on the electrode, the capacitance value of the capacitance Cx to the ground changes to Cx'. According to the formula (1), the electric quantity measured by the measuring unit 45 at this time: Q45'=Cx'*(V1-V2) -Cb(V3_s-V3_t). That is, when there is touch, the voltage measured by the measuring unit 45 is: V45' = K * Q45' = K * (Cx' * (V1 - V2) - Cb (V3_s - V3_t)) (2).

It can be obtained that when there is touch on the sensing electrode, the voltage variation caused by the measuring unit 45 is: ΔV45=V45'-V45=K*(Q45'-Q45)=K(Cx'-Cx)*(V1 -V2) = ΔCx * K * (V1 - V2) (3).

It can be seen from the equation (3) that the amount of change ΔCx of the capacitance value of the ground capacitance Cx of the sensing electrode can be obtained according to the variation amount ΔV45 of the voltage measured by the measuring unit 45, and the amount of change ΔCx represents the sensing of the touch. The amount of the touch can be known by the amount of change ΔCx.

Normally, when the screen is touched with a finger, since one finger can cover 2 to 3 sensing electrodes, the amount of change in the amount of touch ΔCx is relatively large, and the above measured data is not too large. deviation. However, when using a passive pen touch, since the touch area of the passive pen and the sensing electrode is small, the capacitance of the sensing electrode to the ground capacitance Cx is caused. The value of the change ΔCx is very small. If you do not do any processing, directly use the analog-to-digital converter to quantify the equations (1) and (2), which will make the equation (3) only use the analog-to-digital converter. A part of the quantization range causes problems such as inaccurate quantization and excessive error.

It can be seen from the equations (1) and (2) that the variation range of ΔV45 can be changed by adjusting the values of the gain K and the adjustment capacitor Cb. Assume that the range of the analog-to-digital converter scale used for quantization is Vm~Vh. Then, for small signals, the most ideal case is that ΔV45 in (3) can occupy all or most of the range of (Vh-Vm), so that even small changes will quantify large differences, which is advantageous. Improve the resolution of the analog. The specific adjustment method is as follows: First, adjust the value of the capacitance Cb and the gain K such that V45 in the equation (1) is equal to or close to Vm, and the difference between V45 and Vm may be different according to the application of the system, and at the same time, the capacitance Cb is adjusted and The value of K makes V45' in equation (2) equal to or close to Vh, and the difference between V45' and Vh may vary depending on the system application. After such adjustment, ΔV45 of the equation (3) can occupy most of the range of (Vh - Vm), thereby improving the quantization accuracy.

In practical applications, after detecting a touch, it may be determined whether the touch object is a hand or a passive pen, which may be determined according to the number of sensing electrodes covered by the touch or the characteristics of the touch object, and then for different touches. The control object sets different capacitance values of the adjustment capacitor Cb and the value of the gain K to accurately detect the touch position of different touch objects.

FIG. 7 shows a touch detection method according to an embodiment of the present invention flow chart. When a touch occurs on the sensing electrode, the capacitance of the sensing electrode changes. This amount of change is converted into a digital quantity by an analog digital converter (ADC), and the touch signal can be recovered. Generally, the capacitance change amount and the sensing amount. The electrodes are related to the area covered by the touch.

In this embodiment, a method of detecting a touch position is specifically described below.

Driving the sensing electrode (step S701); driving the sensing electrode disposed on the capacitive touch screen substrate with a voltage source or a current source; adjusting the test accuracy (step S702); adjusting the sensing by using the adjusting capacitor Cb according to different touch objects The accuracy of the electrode test.

The sensing data is detected (step S703); the voltage or frequency or the amount of power of the sensing electrode is detected according to the set test accuracy.

The touch position is determined (step S704).

According to the sensing voltage or the frequency or the amount of electric energy of the sensing electrode and the coordinate corresponding to the touched sensing electrode, the coordinate of the finger touch position can be obtained by using the center of gravity algorithm. For example, when a touch occurs, the sensing electrodes 2a/2b/2c/2d in FIG. 2 are covered by the fingers, and the corresponding sensing data are PT1, PT2, PT3, and PT4, respectively, assuming that we position the horizontal coordinate in the x direction, The ordinate is positioned in the y direction, and the coordinates corresponding to the sensing electrodes 2a-2d are x1, x2, x3, and x4, respectively. The coordinates of the finger touch position obtained by the center of gravity algorithm are: Xtouch=(PT1*x1+PT2*x2+PT3*x3+PT4*x4)/(PT1+PT2+PT3+PT4)

Here only the one-dimensional center of gravity algorithm is used, and the actual coordinates are determined by the two-dimensional center of gravity algorithm.

In this embodiment, the adjustable reference adjustment capacitor Cb can be used to adjust the test accuracy of the sensing electrode according to different touch objects, and different test objects are used to detect the voltage or frequency or the amount of charge of the sensing electrode for different touch objects, thereby achieving touch. Accurate detection of the control position.

The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the invention. Therefore, the present invention should not be limited to the disclosed embodiments, but the broadest scope consistent with the principles and novel features disclosed herein.

Although the technical content of the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention, and any modifications and refinements made by those skilled in the art without departing from the spirit of the present invention are encompassed by the present invention. The scope of protection of the present invention is therefore defined by the scope of the appended claims.

10‧‧‧Touch Control Wafer

11‧‧‧Capacitive touch screen

15‧‧‧Optical adhesive

16‧‧‧Substrate

17‧‧‧heteroconductive film

18‧‧‧ Coverage

19‧‧‧Induction electrodes

Claims (11)

  1. A capacitive touch screen includes: a substrate: a plurality of sensing electrodes disposed on the substrate, the sensing electrodes are arranged in a two-dimensional array; and a touch control chip disposed on the substrate, the The touch control chip and each of the sensing electrodes are respectively connected by wires. The touch control chip is configured to detect a self-capacitance change of each of the sensing electrodes by using a detecting circuit with adjustable test precision. And determine a touch signal.
  2. The capacitive touch screen of claim 1, wherein the detecting circuit with adjustable test precision comprises: a power source; a capacitor to be tested has one end grounded, and the other end is connected to the power source through a switch, the capacitor to be tested The capacitance value changes when there is a touch; a tunable capacitor is connected to the power source at both ends, and the test accuracy of the detection circuit is adjusted by changing the value of the self-capacitance; and a measuring unit is connected to the tunable capacitor according to the detecting circuit The test accuracy tests the amount of self-capacitance change of each of the sensing electrodes.
  3. The capacitive touch screen of claim 2, wherein the power source has a single frequency or a plurality of frequencies.
  4. The capacitive touch screen of claim 1, wherein the touch control chip detects the self-capacitance change of each of the sensing electrodes by using the detecting circuit with adjustable test precision, including: using the detecting circuit with adjustable test precision At the same time, the amount of self-capacitance change of each of the sensing electrodes is detected.
  5. The capacitive touch screen of claim 1, wherein the touch control chip detects the self-capacitance change of each of the sensing electrodes by using the detecting circuit with adjustable test precision, including: using the detecting circuit with adjustable test precision The packet detects the amount of self-capacitance change of each of the sensing electrodes.
  6. The capacitive touch screen of claim 1, wherein the substrate is a glass substrate, and the touch control wafer is disposed on the substrate in a glass flip-chip manner.
  7. The capacitive touch screen of claim 1, wherein the substrate is a flexible substrate, and the touch control wafer is disposed on the substrate in a flexible flip chip manner.
  8. The capacitive touch screen of claim 1, wherein the substrate is a printed circuit board, and the touch control wafer is disposed on the substrate in an on-chip chip package.
  9. The capacitive touch screen of claim 1, wherein the sensing electrodes are rectangular, diamond, circular or elliptical in shape.
  10. A capacitive touch screen includes: a substrate; a plurality of sensing electrodes disposed on the substrate, the sensing electrodes are arranged in a two-dimensional array; and a plurality of touch control wafers are disposed on the substrate Each of the touch control chips and the corresponding ones of the sensing electrodes are respectively connected by wires, and each of the touch control chips is configured as A touch detection signal is determined by detecting a self-capacitance change amount of each of the sensing electrodes by using a detection circuit with adjustable test precision.
  11. The capacitive touch screen of claim 10, wherein the touch control chips are synchronized or not synchronized.
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TWI584184B (en) * 2016-02-19 2017-05-21 聯陽半導體股份有限公司 Touch detection device and touch detection method
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